准噶尔盆地南缘井井子沟组露头沉积特征及模式  

Sedimentary Characteristics and Model of Outcrop in Jingjingzigou Formation of Southern Margin, Junggar Basin

作　　者：张驰 于兴河[1] 李顺利[1] 陈宏亮[1] 杨志浩[1] 李亚龙[1] ZHANG Chi;YU Xinghe;LI Shunli;CHEN Hongliang;YANG Zhihao;LI Yalong(School of Energy Resources, China University of Geosciences, Beijing 100083, China)

机构地区：[1]中国地质大学能源学院,北京100083

出　　处：《新疆石油地质》2017年第5期544-552,624,共10页Xinjiang Petroleum Geology

基　　金：国家自然科学基金(41472091);国家科技重大专项(2017ZX05001002-004)

摘　　要：针对准噶尔盆地南缘中二叠统井井子沟组地层沉积环境不明、沉积模式存在争议等问题,从四工河和四工河煤矿厂露头剖面着手,详细研究井井子沟组野外沉积特征,精细划分出11种岩相和6种垂向序列,识别出包括冲刷面、岩相变化面以及洪泛面在内的旋回基准面,判断出古气候经历了由湿润还原环境向干旱氧化环境的突变,结合典型剖面解析建立了井井子沟组辫状河三角洲沉积模式。研究表明:准噶尔盆地南缘二叠系井井子沟组沉积多套砂岩和泥岩,颜色以灰色为主并夹多套煤层,可见大量植物化石碎片,表明整体古气候温暖湿润适宜植被生长,中部夹红褐色砂岩,表明经历过一次古气候的突变;主要发育辫状河三角洲沉积,包括水上分流河道、沼泽、分流河道间、水下分流河道、河口坝等微相;砂地比较高,表现出"砂包泥"的特征;在区域构造的影响下,基准面不断上升,受河道下切影响,下降半旋回发育程度较差。To solve the problems that the depositional environment of the Middle Permian Jingjingzigou formation in southern margin ofJunggar basin is unclear and its sedimentary model is controversial,starting from2outcrop profiles such as Sigonghe and Sigonghe CoalMine Plant,the paper makes a detailed study on the sedimentary characteristics of the formation,divides the formation into11lithofaciesand6vertical sequences,identifies cyclic base levels including scour surface,lithofacies transition surface and flooding surface,concludesthe abrupt change of paleoclimate from humid reducing environment to dry oxidation environment,and establishes a sedimentary model ofbraided-river delta for Jingjingzigou formation based on combination with typical profile analysis.The study shows that several sets of sandstones and mudstones deposited in the Jingjingzigou formation in the southern margin of Junggar basin,which are dominated by grey colorand interbedded with several sets of coal beds.Large amount of debris of plant fossils can be noted in the formation,indicating a humidand warm paleoclimate which was suitable for vegetation growth.The interbedded red-brown sandstone in the middle indicates an abruptchange of the paleoclimate.Braided-river delta is mainly developed in the formation including distributary channel,swamp,interdistributary bay,underwater distributary channel and mouth bar etc.Relatively high sandstone ratio shows a characteristic of“mud coated bysand”.The base level rises continuously due to the influence of regional structures and downward half-cycle is poorly developed under theimpact of river channel down-cutting.

关 键 词：准噶尔盆地 南缘 井井子沟组 露头层序 沉积特征 辫状河三角洲 沉积模式 

分 类 号：TE112.3[石油与天然气工程—油气勘探]